As shown in FIG. 1, a conventional high chair 9′ (or stroller) mainly has a seat portion 1′, a backrest 2′, two arms 12′, a frame 4′, and a plurality of wheels 8′, all of which are pivotally connected sequentially. The conventional high chair 9′ further comprises a tray 3′ connected to the arms 12′ and an adjusting unit (not shown) installed at the joint of the backrest 2′ and the seat portion 1′ for adjusting the inclination of the backrest 2′ relative to the seat portion 1′, with only one safety lock.
The position of the adjusting unit results in the inconvenience of assembling the adjusting unit due to confining space. The only one safety lock may results in sudden and large-ranged inclination of the backrest 2′, which frightens or moreover hurts the infants if the high chair 9′ is adjusted when the infants are sitting therein. In addition, either because the height of the tray 3′ connected to the arms 12 and the distance between the tray 3′ and the backrest 2′ cannot be adjusted, or because the distance between the tray 3′ and the backrest 2′ can be adjusted while the height of the tray 3′ cannot be adjusted, the conventional high chair 9′ cannot be adapted for all infants with different statures.